Scared of saying no

I was 22 and used to go to my girlfriend's apartment. It was a one room studio apartment and one night, after having one to many drinks, she began to have s** with her boyfriend right next to me. I was so embarrassed because they were both stark naked, laughing and giggling about it and inviting me to join them. Ended up convinced to take my clothes off and ended upon the floor between them. Fresh little cup caked and ended up with her boyfriends d*** in my mouths and my girlfriend eating out my p****. The wildest thing I ever did and !WOW! did I get f***** that night. Left that night completely sexually satisfied and never mentioned it to my boyfriend.